#include "sys.h"
#include "usart3.h"
#include "stdarg.h"
#include "stdio.h"
#include "string.h"
#include "stm32f4xx.h"

//初始化IO 串口3
//pclk1:PCLK1时钟频率(Mhz)
//bound:波特率
void usart3_init(u32 bound)
{
    NVIC_InitTypeDef NVIC_InitStructure;
    GPIO_InitTypeDef GPIO_InitStructure;
    USART_InitTypeDef USART_InitStructure;

    USART_DeInit(USART3);  //复位串口3

    RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOB, ENABLE); //使能GPIOB时钟
    RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART3, ENABLE);//使能USART3时钟


    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_11 | GPIO_Pin_10; //GPIOB11和GPIOB10初始化
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;//复用功能
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;	//速度50MHz
    GPIO_InitStructure.GPIO_OType = GPIO_OType_PP; //推挽复用输出
    GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP; //上拉
    GPIO_Init(GPIOB, &GPIO_InitStructure); //初始化GPIOB11，和GPIOB10


    GPIO_PinAFConfig(GPIOB, GPIO_PinSource11, GPIO_AF_USART3); //GPIOB11复用为USART3
    GPIO_PinAFConfig(GPIOB, GPIO_PinSource10, GPIO_AF_USART3); //GPIOB10复用为USART3

    USART_InitStructure.USART_BaudRate = bound;//波特率一般设置为9600;
    USART_InitStructure.USART_WordLength = USART_WordLength_8b;//字长为8位数据格式
    USART_InitStructure.USART_StopBits = USART_StopBits_1;//一个停止位
    USART_InitStructure.USART_Parity = USART_Parity_No;//无奇偶校验位
    USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;//无硬件数据流控制
    USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;	//收发模式
    USART_Init(USART3, &USART_InitStructure); //初始化串口3

    USART_ITConfig(USART3, USART_IT_RXNE, ENABLE);//开启中断

    USART_Cmd(USART3, ENABLE);                    //使能串口

    NVIC_InitStructure.NVIC_IRQChannel = USART3_IRQn;
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;//抢占优先级2
    NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;		//子优先级3
    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;			//IRQ通道使能
    NVIC_Init(&NVIC_InitStructure);	//根据指定的参数初始化VIC寄存器

    //USART3_RX_STA=0;				//清零
}



